Supposing that you have some of this stuff already we will try to make a list of everything that belongs in the basic /5 tool kit. Remember there are other tools you will need but this is the on board tool kit. To begin;
5 Hex Key wrenches also called Inner Hex wrenches. You need 3 mm, 4 mm, 5 mm, 6 mm and 8 mm. Ordinary good quality hex wrenches will work fine. But not cheapo ones, they will round off.
Several special tools are needed in the on board tool kit. 71 11 1 237 857 is the ring spanner that fits the swing arm nuts on one end, 27 mm, and the other end fits the center nut and other parts of the front forks, it is 36 mm.
Another special wrench you will need is the hook spanner with pins for the top covers of the fork tubes. It is # 71 11 1 237 858
There is a third special spanner for /5s but I don't have one so I don't know the #.
You need a socket for the spark plugs. The tubular one in the stock kit is a good one. It has a Tommy bar that can also be use to remove stubborn axles. The spark plug socket is #71 11 1 237 856 the Tommy bar is #71 11 2 301 357
There is a special feeler gauge that is still available and belongs in the on board tool kit. It is shorter and makes it much easier to do some of the operations needed. It covers all the sizes needed for the setting of valve lash, ignition point gap, spark plug gap and a setting needed on the brake master cylinder (used only rarely when replacing, rebuilding the MC) It is part # 71 11 9 090 154
You need a test light, a continuity light. They are a common tool for tracing wiring problems. There is a German one made by Stahwillie and is a nice one but a common test light will work fine.
It is recommended to carry a couple of short tire irons. I one several and a long one too. And if using tube tires, which you will be using, a tube patching kit. There is an on board tire pump that has a special place to store on the bike.
There will be more, to be continued.